Question

A group of students painted four cans, placed 500 grams of water in each can, and measured the temperature of the water as shown in Figure 1.They placed the cans on a sunny windowsill for two hours and then measured the temperature again (Figure 2).
•Which statement correctly describes the significance of the temperature changes shown?

A The water molecules in the white can slowed down the most.

B The water molecules in the black can had the largest increase in average kinetic energy.

C The water molecules in the blue can have a lower average potential energy than the water molecules in the white can.

D The water molecules in the yellow can are moving at half the speed of the water molecules in the blue can.

Answer 1

B.The water molecules in the black can had the largest increase in average kinetic energy.

Explanation:

Here, black painted can absorbs more heat than the other color painted cans.

Black color absorbs all the heat and didn't reflect anything back, so it absorbs the most heat.

White color reflects all the heat, so heat absorbed by the white can is least.

When the black can absorbs heat then the water molecules in the can gets its maximum amount of kinetic energy so that the water molecules in the can collide with each other and also along with the walls of the can here, and so the average kinetic energy increases.